Method for optically determining the temperature of a molten metal, and reeling device for carrying out said method

Abstract

A method for optically determining the temperature of a molten metal with a measuring device, including calibrating a replacement measuring chain by a measuring chain as a system-internal measuring standard. The measuring device includes an optical waveguide, to guide electromagnetic radiation emitted from the metal or from the tip of the optical waveguide to an optical detector, at least one replacement optical waveguide, an optical detector for determining the temperature of the metal from an analysis of the electromagnetic radiation, a measuring chain, in which the optical waveguide is the measurement recorder, and at least one replacement measuring chain, in which a replacement optical waveguide is the measurement recorder. A reeling device includes a conveying device for successive reeling of the optical waveguide from a stock and of the replacement optical waveguide from a replacement stock, a receiving device for a stock and at least one replacement stock.

The invention claimed is: 
     
       1. A reeling device comprising:
 a receiving device configured to store an optical waveguide stock of an optical waveguide and a replacement optical waveguide stock of a replacement optical waveguide; 
 a conveying device including a first end coupled to the receiving device and a second end in a vicinity of a molten metal, said conveying device configured to successively convey to the molten metal from said receiving device a first end of said optical waveguide and a first end of said replacement optical waveguide to maintain the first end of the optical waveguide and the first end of the replacement optical waveguide in contact with or in a vicinity of the molten metal; 
 an optical detector configured to:
 receive an optical signal from at least one of a second end of the optical waveguide and a second end of the replacement optical waveguide; and 
 convert the optical signal to an electrical signal corresponding to electromagnetic radiation emitted by the molten metal sensed by the corresponding one of the first end of the optical waveguide and the first end of the replacement optical waveguide. 
 
 
     
     
       2. The reeling device of  claim 1 , wherein the conveying device further includes a fluid input for receiving a flow of fluid into the conveying device which causes one or both of the optical waveguide and the replacement optical waveguide to be conveyed to the molten metal. 
     
     
       3. The reeling device of  claim 1 , wherein the conveying device includes at least two counter-rotating rollers configured to convey one or both of the optical waveguide and the replacement optical waveguide through a gap between the at least two counter-rotating rollers. 
     
     
       4. The reeling device of  claim 3 , wherein at least one roller of the at least two counter-rotating rollers comprises a drive roller. 
     
     
       5. The reeling device of  claim 3 , wherein the at least two counter-rotating rollers are configured to apply a retention force to one or both of the optical waveguide and the replacement optical waveguide to control a quantity of the one or both of the optical waveguide and the replacement optical waveguide conveyed through the conveying device. 
     
     
       6. The reeling device of  claim 1 , further comprising:
 an optical multiplexer coupled to the second end of the optical waveguide, the second end of the replacement optical waveguide, and the optical detector, said optical multiplexer configured to transmit, to the optical detector, the optical signal from one of the second end of the optical waveguide and the second end of the replacement optical waveguide. 
 
     
     
       7. The reeling device of  claim 1 , further comprising:
 a signal analysis module, coupled to the optical detector, and configured to receive the electrical signal from the optical detector and determine a temperature of the molten metal based upon the electrical signal. 
 
     
     
       8. The reeling device of  claim 1 , wherein the optical waveguide stock and the replacement optical waveguide stock are stored on drum winch spools in the receiving device. 
     
     
       9. The reeling device of  claim 1 , wherein the conveying device comprises a fluid line. 
     
     
       10. The reeling device of  claim 1 , further comprising a measuring chain and a replacement measuring chain, wherein the measuring chain includes the optical waveguide and the replacement measuring chain includes the replacement optical waveguide. 
     
     
       11. A method for optically determining a temperature of a molten metal, comprising:
 successively conveying to the molten metal a first end of an optical waveguide and a first end of a replacement optical waveguide from an optical waveguide stock and a replacement optical waveguide stock stored in a receiving device configured to store the optical waveguide stock and the replacement optical waveguide stock, to maintain the first end of said optical waveguide and the first end of said replacement optical waveguide in contact with or in a vicinity of the molten metal, the conveying being by a conveying device having a first end coupled to the receiving device and a second end in the vicinity of the molten metal; 
 receiving, by an optical detector, coupled to one or both of a second end of the optical waveguide and a second end of the replacement optical waveguide, an optical signal sensed by one of the first end of the optical waveguide and the first end of the replacement optical waveguide; 
 converting, by the optical detector, the optical signal to an electrical signal corresponding to electromagnetic radiation emitted by the molten metal; and 
 transmitting the electrical signal to a signal analysis module for determination of the temperature of the molten metal. 
 
     
     
       12. The method of  claim 11 , wherein a measuring chain includes the optical waveguide and a replacement measuring chain includes the replacement optical waveguide. 
     
     
       13. The method of  claim 12 , further comprising:
 calibrating the replacement measuring chain based on the measuring chain as a system-internal measurement standard; and 
 calibrating the replacement measuring chain before consumption of the optical waveguide stock. 
 
     
     
       14. The method of  claim 12 , further comprising:
 calibrating the measuring chain based on a system-external measurement standard. 
 
     
     
       15. The method of  claim 13 , further comprising:
 conveying the first end of the optical waveguide and the first end of the replacement optical waveguide to a common measurement area; 
 wherein calibrating the replacement measuring chain based on the measuring chain as a system-internal measurement standard comprises determining a calibration value based upon a first optical signal sensed by the first end of the optical waveguide and determining a test value based upon a second optical signal sensed by the first end of the replacement optical waveguide. 
 
     
     
       16. The method of  claim 12 , wherein the measuring chain and the replacement measuring chain comprise a branched measuring chain. 
     
     
       17. The method of  claim 11 , further comprising:
 receiving, by an optical multiplexer, connected to the optical waveguide at the second end of the optical waveguide, and to the replacement optical waveguide at second end of the replacement optical waveguide, and connected to the optical detector, a first optical signal from the optical waveguide and a second optical signal from the replacement optical waveguide; and 
 multiplexing, by the optical multiplexer, one of the first optical signal from the optical waveguide and the second optical signal from the replacement optical waveguide as an output of the optical multiplexer; 
 wherein receiving, by the optical detector, the optical signal sensed by one of the first end of the optical waveguide and the first end of the replacement optical waveguide comprises receiving, by the optical detector from the optical multiplexer, the output one of the first optical signal from the optical waveguide and the second optical signal from the replacement optical waveguide. 
 
     
     
       18. The method of  claim 11 , wherein successively conveying to the molten metal a first end of said optical waveguide and a first end of said replacement optical waveguide from said optical waveguide stock and said replacement optical waveguide stock stored in said receiving device comprises:
 inputting, into a fluid input of the conveying device, fluid to cause conveying of the first end of said optical waveguide and the first end of said replacement optical waveguide to the molten metal; and 
 reeling off, from the optical waveguide stock and the replacement optical waveguide stock, the optical waveguide and the replacement optical waveguide to facilitate conveying of the first end of said optical waveguide and the first end of said replacement optical waveguide to the molten metal. 
 
     
     
       19. The method of  claim 11 , wherein conveying the first end of said optical waveguide and the first end of said replacement optical waveguide to the molten metal comprises conveying the first end of said optical waveguide and the first end of said replacement optical waveguide to the molten metal by at least two counter-rotating rollers configured to convey the optical waveguide and the replacement optical waveguide through a gap between the at least two counter-rotating rollers. 
     
     
       20. The method of  claim 19 , further comprising:
 applying, by the at least two counter-rotating rollers, a retention force to the optical waveguide and the replacement optical waveguide to control a quantity of the optical waveguide and the replacement optical waveguide conveyed through the conveying device.